Question

The length and breadth of a rectangular plate are measured to be 14.5cm and 4.2cm resp. Find its area to appropriate significant figures.

Answer 1

$\sf{\underline{\underline{Here}}}$:

$\text{Length}$ = 14.5 cm

$\boxed{14.5}$ $\implies$ $\boxed{3}$ significant figures.

$\text{Breadth}$ = 4.2 cm

$\boxed{4.2}$ $\implies$ $\boxed{2}$ significant figures.


$\sf{\underline{\underline{So}}}$:

$\sf{Area = 14.5 \times 4.2 {cm}^{2}}$

$\sf{Area = 60.90 \:{cm}^{2}}$


$\sf{\underline{\underline{Note}}}$: The answer should be rounded off to two significant figures.


$\sf{\underline{\underline{Therefore}}}$:

The digit to be dropped in the answer 60.⑨0 is 9 (circled) which is greater than 5. So the preceding zero is raised by 1.


$\sf{\underline{\underline{Hence}}}$:

The answer is $\boxed{61\: {cm}^{2}}$

Answer 2

L=14.5

B=4.2

Area = 60.9

By rounding off we will get

61cm^2